Erector Set 20 features simple & sophisticated moving parts. A 3 Volt motor and gear box for faster & easier construction than ever. Truly fun, motorized Erector play for the novice engineer. Packed with 261 parts, your child will create ingenious Erector movement with a plethora of shiny steel girders, plates, nuts & bolts, wheels. Possibilities for Erector designs & construction are virtually endless. Your kids will love playing with the moving Erector models they create in this 20 Model Erector Set. Everything included to build an abundance of moving creations; a dragster, ditch digger, helicopter, hot rod, lunar module, and more. A broad range of eye-catching Erector designs with illustrated instructions. Design your own clever roving Erector contraption. Erector Set 20 Model Set, A perfect starting point for the Erector beginner wanting a hands-on, creative challenge in construction.